Training with a power meter - how and why

Types of power metres

Types of power metres

Power metres have very much come to forefront of the training tool to have in recent years and understanding the information you can gather is crucial. 

They provide a measurement of the force pushed through the pedal and crank and the velocity with which you do it, to give you your power output. 

They come in many different shapes and forms some within the crank, the pedal, the hub etc. They all provide the same thing; your immediate power output measured in watts, displayed immediately on a head unit for example a Garmin 520 or stages head unit.

Different types of power meters
Why you should have one. They are accurate! It's real-time information so that you can gauge your effort. It’s the immediate feedback allowing you to train/race at the correct intensity.

Why a power meter over heart rate?

Heart rate is affected by factors such as hydration, energy levels, ambient air temperature, overall muscle fatigue, caffeine, mood etc. A power metre gives data that is not affected by any external factor, it’s work being done right now where as changes in heart rate (bpm) is a physiological response to power you are putting through the pedals, thus there is a lag time in heart rate reflecting effort. 

It’s work being done right now! 

Accuracy they provide a way to measure your effort immediately; actual workload output rather than heart rate (bpm), which is your response to a given workload. 

HR takes time to respond to changes in effort whereas Power Meters provide instant data.

Used appropriately it will essentially allow – 

  • Perfect pacing
  • Immediate feedback on your effort
  • Train accurately and efficiently
  • Track your fitness
  • Knowledge of when to rest

1. Using your power meter
It is a must to establish your training zones!

The most accurate and efficient way of establishing you training zones is to perform a 20-minute functional threshold power(FTP) test. Your FTP represents the sustainable power output for 60 minutes. Regular assessment can be utilised to set new training zones and identify fitness level.

An FTP test is exhausting! 

Your FTP is something that can be elevated through training properly, and when done, you can ride faster with a higher power output for the same amount of effort.

2. Knowing Your Strengths and Weaknesses
Having a power meter means you can objectively understand your individual strengths and weaknesses as a rider. If you are a time trialist, you would want to have high 20, 30 and 60-minute power, whereas a sprinter would want high 20, 30, and 60 second power. The data from your power meter can help you recognise your weaknesses as they apply to your event. You can then create workouts to address your weakness, and construct a training program for a specific event.

Beyond your ability to put out power over a given time, power data can also show you other strengths and weaknesses. For example, you can see that you may be stronger when you ride a lower cadence, or that you climb best when you stay seated and have a high cadence. Knowing these details can help you pick events that you are best suited for and create race tactics that will help you optimize your efforts.

3. Maximizing Your Training Time
After you’ve identified your weakness, the next step is to improve it through specific sessions. Using a power meter means you can maximize your training time by designing workouts that are very specific to your individual needs. If your race goals include road racing, dialing in workouts like over/under intervals that require riding below and above threshold can teach your body to clear lactate much like dealing with surges on race day. If you are a time trialist or training for alpine climbs - the pace can be practiced in training and developed through riding in the 88 to 93 percent FTP zone referred to as sweet spot or by working just at threshold.

Also, by tracking changes in threshold, workouts can be incrementally adapted to fitness changes, continuing to challenge the athlete and stimulate physiological change. A power meter is going to show the watts being generated whether it is windy, hilly, raining or hot.

Unlike using speed as a metric, it is consistent to effort.

4. Data Analysis
Power meters take the guesswork out of training!

A program which we utilise to interpret the power metre data is Training Peaks. Useful information provided by this programme is the peak power chart; a chart that tracks you power output over given periods of time; 3 seconds, 10 seconds, 5 minutes, 1hr etc. It’s a great chart to measure improvements over time week by week, month by month, season by season, identify weaknesses and strengths specific to your goal.

Manage fatigue, be fresh for event day.

Another useful feature is the performance management chart. It plots the intensity of training session, and calculate the training stress balance; how tired you are compared with how much training you have done.

Understanding the data allows for knowledge of when to alter intensity of a specific training programme, to allow for recovery, and for the training to take effect.

5. Race Day Planning
Finally, a power meter can take all of the guesswork out of racing. Not only does an athlete know what numbers to look for during the event, but it is also clear what the individual is capable of before combusting. This allows for proper pacing and race execution, especially when combined with Best Bike Split.

A distance event is an excellent example. Using FTP and comparing the watts generated in a given workout allows for determination of the Intensity Factor of that workout.

This metric is good for comparison between the intensity of every race or workout that is completed on a bicycle. 

In summary, a power meter is a great tool for every cyclist. It teaches you how to ride stronger, more consistently and allows for tracking, planning and training with specific focus on your unique needs and goals.

Fig 1. 

Power/Training Zones
1. Active Recovery (<54% FTP)
– Social pace with very little physiological effect on your body. Can be used in between intervals and for recovery rides. 

2. Endurance (55% - 74% FTP)
– Easy pace that you could ride all day long. Conversation is still possible with little concentration required. 

3. Tempo (75% - 89%  FTP)
– Brisk pace that can be maintained for a few hours that requires concentration when riding alone. Breathing in tempo is rhythmic and may become strained at the upper end of this zone.

4. Threshold (90% - 104% FTP)
– Moderate to hard effort and leg sensations that can be maintained for up to 1 hour. Conversation is difficult and concentration is required.

5. VO2Max (105% - 120% FTP)
– Power that is primarily taxing your VO2Max system. Leg sensations are high and conversation is not possible. VO2Max can be maintained for 3-8 minutes.

6. Anaerobic (120% - 149% FTP)
– Extremely hard efforts with severe leg sensations that can be maintained for 30 seconds up to 3 minutes.

7. Neuromuscular (>150% FTP)
– Sprinting power that is taxing your neuromuscular system and can be maintained for 1-20 seconds.